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Pamela Byrd - One of the best experts on this subject based on the ideXlab platform.
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Mitotic arrest in PtK2 cells induced by microinjection of a rabbit antiserum and affinity‐purified antibodies against a 66‐kDa PtK2 cell polypeptide
Cytoskeleton, 1996Co-Authors: Pamela Byrd, Dwayne Wise, William L DentlerAbstract:: Cell division was arrested by injection of a preimmune rabbit serum, B-61, into PtK(2) cells during interphase and Prometaphase. Identical results were obtained by injection of whole B-61 antiserum and of antibodies affinity-purified from the serum against a 66-kDa PtK(2) cell polypeptide. When injected into interphase cells, the antibodies arrested further development and cell division. When injected into Prometaphase and metaphase cells, spindles shortened and poles moved together at a rate of 0.2-0.4 mu m/min, approximately half the rate of anaphase A chromosome movements in normally dividing PtK(2) cells. Chromosomes decondensed and cells did not reenter division. Both whole antisera and affinity-purified antibodies stained antigens diffusely localized throughout the cytoplasm in dividing and interphase cells. These results suggest that the 66-kDa antigen is a nonspindle protein that may regulate mitotic progression in PtK(2) cells.
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mitotic arrest in ptk2 cells induced by microinjection of a rabbit antiserum and affinity purified antibodies against a 66 kda ptk2 cell polypeptide
Cytoskeleton, 1996Co-Authors: Dwayne Wise, Pamela Byrd, William L DentlerAbstract:: Cell division was arrested by injection of a preimmune rabbit serum, B-61, into PtK(2) cells during interphase and Prometaphase. Identical results were obtained by injection of whole B-61 antiserum and of antibodies affinity-purified from the serum against a 66-kDa PtK(2) cell polypeptide. When injected into interphase cells, the antibodies arrested further development and cell division. When injected into Prometaphase and metaphase cells, spindles shortened and poles moved together at a rate of 0.2-0.4 mu m/min, approximately half the rate of anaphase A chromosome movements in normally dividing PtK(2) cells. Chromosomes decondensed and cells did not reenter division. Both whole antisera and affinity-purified antibodies stained antigens diffusely localized throughout the cytoplasm in dividing and interphase cells. These results suggest that the 66-kDa antigen is a nonspindle protein that may regulate mitotic progression in PtK(2) cells.
William L Dentler - One of the best experts on this subject based on the ideXlab platform.
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Mitotic arrest in PtK2 cells induced by microinjection of a rabbit antiserum and affinity‐purified antibodies against a 66‐kDa PtK2 cell polypeptide
Cytoskeleton, 1996Co-Authors: Pamela Byrd, Dwayne Wise, William L DentlerAbstract:: Cell division was arrested by injection of a preimmune rabbit serum, B-61, into PtK(2) cells during interphase and Prometaphase. Identical results were obtained by injection of whole B-61 antiserum and of antibodies affinity-purified from the serum against a 66-kDa PtK(2) cell polypeptide. When injected into interphase cells, the antibodies arrested further development and cell division. When injected into Prometaphase and metaphase cells, spindles shortened and poles moved together at a rate of 0.2-0.4 mu m/min, approximately half the rate of anaphase A chromosome movements in normally dividing PtK(2) cells. Chromosomes decondensed and cells did not reenter division. Both whole antisera and affinity-purified antibodies stained antigens diffusely localized throughout the cytoplasm in dividing and interphase cells. These results suggest that the 66-kDa antigen is a nonspindle protein that may regulate mitotic progression in PtK(2) cells.
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mitotic arrest in ptk2 cells induced by microinjection of a rabbit antiserum and affinity purified antibodies against a 66 kda ptk2 cell polypeptide
Cytoskeleton, 1996Co-Authors: Dwayne Wise, Pamela Byrd, William L DentlerAbstract:: Cell division was arrested by injection of a preimmune rabbit serum, B-61, into PtK(2) cells during interphase and Prometaphase. Identical results were obtained by injection of whole B-61 antiserum and of antibodies affinity-purified from the serum against a 66-kDa PtK(2) cell polypeptide. When injected into interphase cells, the antibodies arrested further development and cell division. When injected into Prometaphase and metaphase cells, spindles shortened and poles moved together at a rate of 0.2-0.4 mu m/min, approximately half the rate of anaphase A chromosome movements in normally dividing PtK(2) cells. Chromosomes decondensed and cells did not reenter division. Both whole antisera and affinity-purified antibodies stained antigens diffusely localized throughout the cytoplasm in dividing and interphase cells. These results suggest that the 66-kDa antigen is a nonspindle protein that may regulate mitotic progression in PtK(2) cells.
Juan F Gimenezabian - One of the best experts on this subject based on the ideXlab platform.
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regulation of sister chromatid cohesion between chromosome arms
Current Biology, 2004Co-Authors: Toru Hirota, Izabela Sumara, Juan F Gimenezabian, Consuelo Torre, Silke Hauf, Daniel W Gerlich, Jan Ellenberg, Jan-michael PetersAbstract:Sister chromatid separation in anaphase depends on the removal of cohesin complexes from chromosomes [1]. In vertebrates, the bulk of cohesin is already removed from chromosome arms during prophase and Prometaphase [2, 3], whereas cohesin remains at centromeres until metaphase, when cohesin is cleaved by the protease separase [3, 4]. In unperturbed mitoses, arm cohesion nevertheless persists throughout metaphase and is principally sufficient to maintain sister chromatid cohesion [5]. How arm cohesion is maintained until metaphase is unknown. Here we show that small amounts of cohesin can be detected in the interchromatid region of metaphase chromosome arms. If Prometaphase is prolonged by treatment of cells with microtubule poisons, these cohesin complexes dissociate from chromosome arms, and arm cohesion is dissolved. If cohesin dissociation in Prometaphase-arrested cells is prevented by depletion of Plk1 or inhibition of Aurora B, arm cohesion is maintained. These observations imply that, in unperturbed mitoses, small amounts of cohesin maintain arm cohesion until metaphase. When cells lacking Plk1 and Aurora B activity enter anaphase, chromatids lose cohesin. This loss is prevented by proteasome inhibitors, implying that it depends on separase activation. Separase may therefore be able to cleave cohesin at centromeres and on chromosome arms.
Dwayne Wise - One of the best experts on this subject based on the ideXlab platform.
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Mitotic arrest in PtK2 cells induced by microinjection of a rabbit antiserum and affinity‐purified antibodies against a 66‐kDa PtK2 cell polypeptide
Cytoskeleton, 1996Co-Authors: Pamela Byrd, Dwayne Wise, William L DentlerAbstract:: Cell division was arrested by injection of a preimmune rabbit serum, B-61, into PtK(2) cells during interphase and Prometaphase. Identical results were obtained by injection of whole B-61 antiserum and of antibodies affinity-purified from the serum against a 66-kDa PtK(2) cell polypeptide. When injected into interphase cells, the antibodies arrested further development and cell division. When injected into Prometaphase and metaphase cells, spindles shortened and poles moved together at a rate of 0.2-0.4 mu m/min, approximately half the rate of anaphase A chromosome movements in normally dividing PtK(2) cells. Chromosomes decondensed and cells did not reenter division. Both whole antisera and affinity-purified antibodies stained antigens diffusely localized throughout the cytoplasm in dividing and interphase cells. These results suggest that the 66-kDa antigen is a nonspindle protein that may regulate mitotic progression in PtK(2) cells.
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mitotic arrest in ptk2 cells induced by microinjection of a rabbit antiserum and affinity purified antibodies against a 66 kda ptk2 cell polypeptide
Cytoskeleton, 1996Co-Authors: Dwayne Wise, Pamela Byrd, William L DentlerAbstract:: Cell division was arrested by injection of a preimmune rabbit serum, B-61, into PtK(2) cells during interphase and Prometaphase. Identical results were obtained by injection of whole B-61 antiserum and of antibodies affinity-purified from the serum against a 66-kDa PtK(2) cell polypeptide. When injected into interphase cells, the antibodies arrested further development and cell division. When injected into Prometaphase and metaphase cells, spindles shortened and poles moved together at a rate of 0.2-0.4 mu m/min, approximately half the rate of anaphase A chromosome movements in normally dividing PtK(2) cells. Chromosomes decondensed and cells did not reenter division. Both whole antisera and affinity-purified antibodies stained antigens diffusely localized throughout the cytoplasm in dividing and interphase cells. These results suggest that the 66-kDa antigen is a nonspindle protein that may regulate mitotic progression in PtK(2) cells.
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antikinetochore antibodies interfere with Prometaphase but not anaphase chromosome movement in living ptk2 cells
Cytoskeleton, 1992Co-Authors: Dwayne Wise, Lakshmisri BhattacharjeeAbstract:Injection of CREST antikinetochore antiserum (AKA) containing antibodies to the kinetochore into living Prometaphase PtK2 cells decreased chromosome velocity to near zero. Injection of either phosphate-buffered saline or CREST antiserum without antikinetochore antibodies (antikinetochore negative: AKN) had no effect on Prometaphase oscillations. AKA antiserum injected into anaphase cells at the beginning of chromatid separation had no effect on anaphase chromosome velocity, spindle elongation, or cytokinesis. Visible binding of antikinetochore antibodies in Prometaphase cells at room temperature occurred between 5 and 15 minutes after injection. Anaphase cells injected at the beginning of chromatid separation had bound antibody at the end of anaphase. AKA antiserum recognizes in Western blots proteins associated with the primary constriction: CENP-B, -C, and -D, as reported by other workers. The control antiserum, AKN, does not recognize these proteins. These results imply that the antigens recognized by CREST antibodies are important for chromosome movement. Whether or not these antigens are themselves motor molecules cannot be addressed by the present data. In addition, the results suggest that these antigens are not involved in an important way in anaphase movement. © 1992 Wiley-Liss, Inc.
Claude Prigent - One of the best experts on this subject based on the ideXlab platform.
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Aurora A kinase activity is required to maintain an active spindle assembly checkpoint during Prometaphase.
Journal of cell science, 2018Co-Authors: Thibault Courtheoux, Alghassimou Diallo, Arun Prasath Damodaran, David Reboutier, Erwan Watrin, Claude PrigentAbstract:During the Prometaphase stage of mitosis, the cell builds a bipolar spindle of microtubules that mechanically segregates sister chromatids for two daughter cells in anaphase. The spindle assembly checkpoint (SAC) is a quality control mechanism that monitors proper attachment of microtubules to chromosome kinetochores during Prometaphase. Segregation occurs only when each chromosome is bi-oriented with each kinetochore pair attached to microtubules emanating from opposite spindle poles. Overexpression of the protein kinase Aurora A is a feature of various cancers and is thought to enable tumour cells to bypass the SAC leading to aneuploidy. Here, we took advantage of a chemical and chemical-genetic approach to specifically inhibit Aurora A kinase activity in late Prometaphase. We observed that a loss of Aurora A activity directly affects SAC function, that Aurora A is essential for maintaining the checkpoint protein Mad2 on unattached kinetochores, and that inhibition of Aurora A leads to SAC extinction, even in the presence of nocodazole or taxol. This is a new finding that should affect the way Aurora A inhibitors are used in cancer treatments.
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Aurora A kinase activity is required to maintain an active spindle assembly checkpoint during Prometaphase
Journal of Cell Science, 2018Co-Authors: Thibault Courtheoux, Alghassimou Diallo, Arun Prasath Damodaran, David Reboutier, Erwan Watrin, Claude PrigentAbstract:During the Prometaphase stage of mitosis, the cell builds a bipolar spindle of microtubules that mechanically segregates sister chromatids between two daughter cells in anaphase. The spindle assembly checkpoint (SAC) is a quality control mechanism that monitors proper attachment of microtubules to chromosome kinetochores during Prometaphase. Segregation occurs only when each chromosome is bi-oriented with each kinetochore pair attached to microtubules emanating from opposite spindle poles. Overexpression of the protein kinase Aurora A is a feature of various cancers and is thought to enable tumour cells to bypass the SAC, leading to aneuploidy. Here, we took advantage of a chemical and chemical-genetic approach to specifically inhibit Aurora A kinase activity in late Prometaphase. We observed that a loss of Aurora A activity directly affects SAC function, that Aurora A is essential for maintaining the checkpoint protein Mad2 on unattached kinetochores and that inhibition of Aurora A leads to loss of the SAC, even in the presence of nocodazole or Taxol. This is a new finding that should affect the way Aurora A inhibitors are used in cancer treatments.This article has an associated First Person interview with the first authors of the paper.
